Invasive species throughout the world present several widely recognized problems. There are ongoing efforts to prevent introduction of invasive species and to control populations of the harmful invaders. Invading species cause significant economic, ecological, and human health effects. Invaders disrupt natural systems, cause the extinction of native species, compromise transportation and agriculture, and damage natural resources. Further, no systematic, proactive approach to combating invasive species is available. Invasive species are dealt with on a one-at-a-time, reactive basis, and those who would solve problems associated with the invaders seem to be always a step behind.
Scientific approaches to understanding species invasions have developed along several lines, but most have been frustrated by the complex and unpredictable nature of such invasions. Specifically, it is difficult to predict which species will invade and which invaders will become serious problems. For example, considerable effort has been expended in outlining characteristics of species likely to invade, or of invaders likely to become pests. Another line of inquiry and effort has focused on modeling spatial patterns of range expansion after initial invasion. In spite of significant research, an effective approach to understanding species invasions is lacking and desperately needed.
Existing approaches to the challenges presented by species invasions are reactive in nature, and for that reason will always be “catching up” to the most recent problem. Species that have managed to invade a particular region become the focus of intense activity and attention, and solutions are designed to eradicate the species, usually in the form of measures of control and abatement. This scenario, however, does not prevent invasions, and will perpetually lag behind the most recent invasion.